The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1989
Filed:
Jun. 30, 1988
Lawrence H Ragan, Richardson, TX (US);
AT&E Corporation, San Francisco, CA (US);
Abstract
A wristwatch FM subcarrier paging receiver architecture is disclosed that overcomes the many inherent problems (such as self-oscillation, image responses, spurious local oscillator radiation and interference from entertainment programming) that are encountered in this demanding application. The disclosed architecture includes a tunable notch filter front end, an image cancelling mixer, an automatic gain control circuit, a phase detector for linear detection, frequency feedback for distortion reduction, a synthesized local oscillator, and a frequency plan which can utilize both high and low side local oscillator injection to optimize performance in anticipated interference environments.